Thrust Manipulation Versus Non-Thrust Manipulation

Inclusion Criteria: * Patients, age 18 and older, with mechanically producible low back pain, who attend care at a physical therapy outpatient setting, will be screened for eligibility for the study. * For patients to meet inclusion requirements, they had to display a within session change in pain and/or range of motion during the assessment phase of the clinical examination. In other words, as the clinician performed their assessment and applied a passive accessory assessment technique, the pain and/or range of motion improved during that session, which suggests a favorable outcome using a comparable treatment technique. This is hallmark clinical finding in the patient response model and has been proposed as both a predictor of a positive outcome and as a prognostic variable toward long-term improvements in impairments. Exclusion Criteria: * The presence of any red flags (i.e., tumor, metabolic diseases, RA, osteoporosis, prolonged history of steroid use, etc.) * Signs consistent with nerve root compression (reproduction of low back or leg pain with straight leg raise at less than 45° * Muscle weakness involving a major muscle group of the lower extremity, * Diminished lower extremity muscle stretch reflex * Diminished or absent sensation to pinprick in any lower extremity dermatome) * Other exclusion criteria included prior surgery to the lumbar spine and current pregnancy